Control device for machine guns



Aug. 5, 1930. L. BEAUJARD CONTROL DEVICE FOR MACHINE GUNS Filed Nov. 3, 1928 MM .0 2 W e mm f hm z w 22 mnwf M mam m7 i Patented Aug. 5, 1930 PATENT OFFICE LOUIS BEAUJARD, OF PARISgFRANCE CONTROL DEVICE roa MAortinE GUNS Application filed November 3, 1828, Serial No. 317,036, and in Belgium November 14, 1927.

My invention relates to the electric control of machine guns of the type operated from the recoil of gas thereof and firingthrough or beyond the radius of an aerial propeller.

As is well known, by those skilled in the art, high altitudes subject a machine gun to a natural reduction of surrounding pressure whichconsiderably affects its inner and outer mechanism as well as its synchronism, resulting in very serious drawbacks, which lead to irregularity in firing, causing missfires, and in case of defective adjustment, rupture of the propeller. This abnormal operation arises from the more rapid expansion of the gases. and in order to avoid these serious drawbacks it is necessary to re lace the recuperating spring by a spring of less strength. the result being to increase the operating power when the machine gun is utilized at low altitudes. that is. when the mechanism is no longer exposed to the effects of reduced pressure.

My improved electro-mechanical movement differs largely from the mechanism 0 the prior art and possesses numerous advantages thereover with res ect to operation and adjustment. The general obiect of my invention is to provide an elastic device which compensates for the reduction in atmospheric pressu e and preserves regularity of synchronism during operation.

At high altitudes. immediately after the discharge, the subnormal pressure of the gases being no longer sufficient to return the reloading plunger to its original position, an electro-magnet is adapted to compensate this reduction in pressure and stresses the recuperating spring, which tripped, by a second electro magnet operates the percussion trigger. p

The invention will be more readily understood with reference tothe accompanying drawing illustrating an embodiment ofthe invention by way of example.

In the drawing F ig. 1 is a diagrammatic view partly in section of my control device as applied to machine gun;

Fig. 2 is a f this dynamo diagram illustrating the positionof the propeller with respect to the setting of the device;

Fig. '3 is a diagram illustrating the setting for firing; and

Fig. 4 is a diagram showing the distribution for two machine guns.

Referring to the drawing more in detail, a solenoid B (Fig. 1) is designed to compensate or supplement the movement of displacement of the recharging plunger B of the machine gun in View of the high altitudes and after the discharge, when the pressure of the gases is no longer suflicient to bring back the said plunger to its initial position. The recuper-' ator spring is stressed and the second electro-magnet Cdraws on the retaining spring C of the plunger P for firing. This electromagnet is mounted in a circuit which will be described hereinafter.

The current is furnished from a dynamo D of special type which may be mounted in different ways without, however, being exposed to critical movements. For instance, may be mounted at the extremity of the crank shaft at the rear of the engine or it may be operated by a chain, by a Cardan shaft and oblique axle.

The said dynamo furnishes a current of uniform intensity suitable for energizing, even when the motor is running slow or at high velocity, the synchronizing electro-magnets which are alternatively controlled by a distributer device of special construction illustrated in Fig. 4 and which comprises as many contact plates as there are machine guns to be operated.

The sequence of firing is substantially the same in setting as with machine guns having mechanical control.

As regards the setting of the device, the position of the propeller is supposed to be in the vertical axis of the distributor (Figs. 2 and 3) when the brush A will be in contact. with the corresponding pole plate a displaced through 20 with respect to the axis m-y. When the propeller has passed this axis by an amount of 20 to 25, the discharge takes place. The ball having cleared the air space, i

the gases expand in the usual manner into the chamber, force back the plunger P so as to stress the recuperating spring. In case of reduced pressure at high altitudes, this movement is compensated for by the second electro-ma'gnet B which receives current through the intervention of the following contact plate 6 located at a few degrees from the plate a receiving the current as soon as the ball reaches the orifice of the firearm.

A switch I located in the circuit and within reach of the pilot, enables the mechanism to be placed in and out of operation.

When utilizing twomachine guns within the zone of the radiusof the propeller (Fig. 4) there will be the production of synchronism for one percussion of each gun per revolution of the engine and always lagging opposite blades of the propeller.

The dynamo D employed replaces with advantage the generator driven by air, which is subject to getting out of order and only supplies acurrent which varies in intensity according to the velocity of the aircraft. I

I preferably also utilize the dynamo for energizing a shunt circuit in which an electric heater is inserted, which heater is disposedin the casing of the machine gun for heating the air therein. In order that the loss of heat by conduction will be reduced to a minimum, I preferably support all parts secured to the casing by means of heat-insulating washers whereby the apparatus and the casing are separated from each other from a heat conducting standpoint.

My invention may, moreover, be applied in Having described my invention, what- I claim as new and desire to secure by Letters Patent is 1. In an electric control device for machine guns of the type described, the combination of the recuperator spring is below normal, 2. re-

taining spring for said plunger, and a second electromagnet' for tripping said retaining spring to fire said machine gun.

' 2. In an electric control device for machine guns as set forth in claim 1, the combination of a dynamo for energizing said electro-magnets of constant output. and distributingmeans for controlling the circuits of said ing displaced through substantially 20 with respect to a propeller axis for firing through the blades thereof when the device is used in connection with air craft.

4. In an electric control device for machine guns of the type described, the combination of compensating means adapted to bring back the reloading and firing plunger of said macliine'gun to its initial position when the pressure of the gases which stress the recuperator spring is below normal, and electro-magnetic means for releasing said loading and firing plunger when in said initial position.

5. In an electric control device for machine guns of the type described, the combination of compensating means adapted to bring back the reloading and firing plunger of said machine gun to its initial position when the'pressure of the gases which stress the recuperator spring is below normal, electromagnetic means for releasing said loading and firing plunger when in said initial position, a dynamo for energizing said electro-magnets of constant output, and distributingmeans for controlling the circuits of said dynamo in accordance with the number of machine guns to be operated.

6. In an electric control device for machine guns of the type described, the combination of compensating means adapted to bring back the reloading and firing plunger of said machine gun to its initial position when the pressure of the gases which stress the recuperator spring is below normal, electromagneticmeans for releasing said loading and firing plunger when in said initial position, a dynamo for energizing said electro-magnets of constant output, and a plurality of contact plates corresponding in number to the number of machine guns to be operated cooperating with said dynamo, said plates being displaced through substantially 20 with respect to a propeller axis for firing through theblades thereof when the device is used in signature.

LOUIS BEAUJARD.

dynamo in accordance with the number of machine guns to be operated. v

- 3. In an electric control devicefor machine guns as set-forth in claim 1, the combination of a dynamo of constant output for energizing said electro-magnets, and a plurality of contact plates corresponding in number to .the number of machine guns to be operated so operating with said dynamo, said plates be- 

